I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20

What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 17/03/15 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20


What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

Could form the basis of a serious home brew UPS for prolonged power
outages - if you collect a load of batteries....

"Tim Watts" wrote in message
...
On 17/03/15 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20


What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

Could form the basis of a serious home brew UPS for prolonged power
outages - if you collect a load of batteries....

Mate of mine almost entirely solar powers his entire house that way,
with a load of free batteries that have come out of telephone exchanges.

The 5KW is used to do the cooking electrically using conventional
appliances.

On Tue, 17 Mar 2015 20:52:19 -0000, Roger Mills wrote:

I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20

What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

I had a 3kW one. I often used it to run things like a lawnmower or a hedge trimmer from the car battery instead of finding the extension cord. If I had a huge place, I could have a few people all mowing and trimming at once. Just leave the engine running.

--
Paper clips are the larval stage of coat hangers.

On 17/03/2015 21:03, Tim Watts wrote:
On 17/03/15 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20



What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

Could form the basis of a serious home brew UPS for prolonged power
outages - if you collect a load of batteries....


Well yes, you probably *could* use it for that - but that's not the way
it's being marketed.

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever that is.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

"Roger Mills" wrote in message
...
On 17/03/2015 21:03, Tim Watts wrote:
On 17/03/15 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20



What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

Could form the basis of a serious home brew UPS for prolonged power
outages - if you collect a load of batteries....


Well yes, you probably *could* use it for that - but that's not the way
it's being marketed.

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever that is.

It’s a set of steps that are close to a sinewave than a square wave is.

In article ,
Tough Guy no. 1265 wrote:
I had a 3kW one. I often used it to run things like a lawnmower or a
hedge trimmer from the car battery instead of finding the extension cord.

You find it easier to lug around a car battery - and faff around
connecting an inventor - than using a mains extension?

Figures.

--
*Who is this General Failure chap anyway - and why is he reading my HD? *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 18 Mar 2015 01:24:02 -0000, Dave Plowman (News) wrote:

In article ,
Tough Guy no. 1265 wrote:
I had a 3kW one. I often used it to run things like a lawnmower or a
hedge trimmer from the car battery instead of finding the extension cord.

You find it easier to lug around a car battery - and faff around
connecting an inventor - than using a mains extension?

Figures.

Lug around? No, I turn the key in the ignition and it moves itself.


--
Why is bra singular and panties plural?

Sounds a bit expensive as well even with the discount.
You would need some serious sized battery leads and about five heavy duty
lorry batteries to stand any chance of being able to use it near its limit
and of course what about charging them up?
Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Roger Mills" wrote in message
...
I see that Maplin have a 5000watt mains inverter on offer for £350 instead
of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20

What possible use is it? How many people have got 12v batteries capable of
delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to run
lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

But those tyre marks on the other end of the lawn are a bit awkward...
Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Tough Guy no. 1265" wrote in message
news
On Wed, 18 Mar 2015 01:24:02 -0000, Dave Plowman (News)
wrote:

In article ,
Tough Guy no. 1265 wrote:
I had a 3kW one. I often used it to run things like a lawnmower or a
hedge trimmer from the car battery instead of finding the extension
cord.

You find it easier to lug around a car battery - and faff around
connecting an inventor - than using a mains extension?

Figures.

Lug around? No, I turn the key in the ignition and it moves itself.


--
Why is bra singular and panties plural?

In message , at 20:52:19 on Tue, 17
Mar 2015, Roger Mills remarked:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...inverter-a59lz
?utm_source=newsletter&utm_medium=email&utm_term= 15P13_W4_D3&utm_content
=Product-1&utm_campaign=15P13-20

What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

Stick it in a canal boat, or note that some of the smaller models are in
Maplin's "trucking products" category. In both cases much bigger
batteries available than in a car.
--
Roland Perry

On 18/03/2015 07:58, Brian Gaff wrote:
Sounds a bit expensive as well even with the discount.
You would need some serious sized battery leads and about five heavy duty
lorry batteries to stand any chance of being able to use it near its limit
and of course what about charging them up?
Brian


Run a battery charger off the inverter output.

"Brian Gaff" wrote in message
...

Sounds a bit expensive as well even with the discount.

Not if you don’t need a network connection.

You would need some serious sized battery leads

Yes.

and about five heavy duty lorry batteries to stand any chance of being
able to use it near its limit

Or some decent deep discharge batterys for free.

and of course what about charging them up?

Use the solar panels.

And get paid for what comes from the solar panels
even if you use it yourself in places actually stupid
enough to have a gross feed in tariff.

"Roger Mills" wrote in message
...
I see that Maplin have a 5000watt mains inverter on offer for £350 instead
of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20

What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

In article ,
"john james" writes:
"Roger Mills" wrote in message
...

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever that is.

It's a set of steps that are close to a sinewave than a square wave is.

It's often a square wave with the addition of an elongated zero section
at each zero crossing. Sometimes, there's the addition of one extra
voltage step between zero and the peak.

Fine for resistive loads.

Works with many inductive loads, but may run at reduced power, and
cause extra eddy current heating in laminated cores (with audiable
noise).

Not so good with capacitive loads and capacitor dropper supplies,
where the impedance of the capacitor is reduced by the high frequency
components, causing higher current than appliance designed for, and
usually extra power dissipation somewhere.

If you need them, pure sine wave inverters have come down very
significantly in price over last couple of years. They are basically
a sine wave generator coupled to a power amplifier with a 230V RMS
output. The amplifier is class D, i.e. high frequency switching, so
the efficiency is almost as high as the "modified" sine wave
inverters (or it can even match, as they're generally better designed,
and the efficiency of the appliance can also be higher in some cases).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Andrew Gabriel" wrote in message
...
In article ,
"john james" writes:
"Roger Mills" wrote in message
...

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever that
is.

It's a set of steps that are close to a sinewave than a square wave is.

It's often a square wave with the addition of an elongated zero section
at each zero crossing.

That's not modified sine wave.

Sometimes, there's the addition of one extra
voltage step between zero and the peak.

That's not modified sine wave either.

Fine for resistive loads.

Works with many inductive loads, but may run at reduced power, and
cause extra eddy current heating in laminated cores (with audiable
noise).

Not so good with capacitive loads and capacitor dropper supplies,
where the impedance of the capacitor is reduced by the high frequency
components, causing higher current than appliance designed for, and
usually extra power dissipation somewhere.

If you need them, pure sine wave inverters have come down very
significantly in price over last couple of years. They are basically
a sine wave generator coupled to a power amplifier with a 230V RMS
output. The amplifier is class D, i.e. high frequency switching, so
the efficiency is almost as high as the "modified" sine wave
inverters (or it can even match, as they're generally better designed,
and the efficiency of the appliance can also be higher in some cases).

On 18/03/2015 09:56, john james wrote:

snipped


"Andrew Gabriel" wrote in message
...
In article ,
"john james" writes:
"Roger Mills" wrote in message
...

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever
that is.

It's a set of steps that are close to a sinewave than a square wave is.

It's often a square wave with the addition of an elongated zero section
at each zero crossing.

That's not modified sine wave.


'Tis, Google it. Rectangular pulses +ve and -ve with gaps between. I
designed one - filthy noisy thing.

Cheers
--
Syd

On Tuesday, 17 March 2015 20:52:20 UTC, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20

What possible use is it?

boats I know someone that brough £10K worth of solar panels for his ~70ft+ steel canal boat.

How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

I think he had 4 gel batteries of about 800Ah each.

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

I'd have thought they'd be of limited interest, but still a possible barging especailly if you want to run anything decent from wind or solar.
But as you say of very limite duse for the average maplin shopper.



--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 17/03/2015 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20


What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

An outdoor concert, run from a van with its engine running, fairly quickly?

It worries me that the uninitiated are going to buying these things to
run lots of mains equipment off their car batteries - only to find that
they're totally useless. [I note that there are no reviews!]

They say it's ideal for running mobile phones!

I agree, they've given an extremely poor indication of its use.

Cheers
--
Syd

Dave Plowman (News) wrote:

You find it easier to lug around a car battery - and faff around
connecting an inventor - than using a mains extension?

Can you use any old inventor, even one who has never invented anything
that's any good, or does it have to be somebody like Alfred Kinsey (who
invented the clitoris)?

Bill

On Wed, 18 Mar 2015 13:27:25 +0000, Bill Wright wrote:

You find it easier to lug around a car battery - and faff around
connecting an inventor - than using a mains extension?

Can you use any old inventor, even one who has never invented anything
that's any good, or does it have to be somebody like Alfred Kinsey (who
invented the clitoris)?

Sounds like Heath Robinson's the man.

Andrew Gabriel wrote:

If you need them, pure sine wave inverters have come down very
significantly in price over last couple of years. They are basically
a sine wave generator coupled to a power amplifier with a 230V RMS
output. The amplifier is class D, i.e. high frequency switching, so
the efficiency is almost as high as the "modified" sine wave
inverters (or it can even match, as they're generally better designed,
and the efficiency of the appliance can also be higher in some cases).


Yes, there's no point in buying the non-sine ones nowadays.

Bill

Tough Guy no. 1265 wrote:

I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...lz?utm_source=

newsletter&utm_medium=email&utm_term=15P13_W4_D3&u tm_content=Product-1&utm_campaign=15P13-20


"Ideal for powering devices such as laptops". **** me, that's overkill
isn't it?

Bill

whisky-dave wrote:



I think he had 4 gel batteries of about 800Ah each.


Must have been a bloody big boat! I wouldn't fancy that sort of weight
except in the bilge!

Bill

Syd Rumpo wrote:
On 17/03/2015 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...5000w-12v-powe

-inverter-a59lz?utm_source=newsletter&utm_medium=email&utm_t erm=15P13_W4_D3&utm_content=Product-1&utm_campaign=15P13-20




What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

An outdoor concert, run from a van with its engine running, fairly quickly?

You don't get anything like 500A out of a van alternator. A row of ten
vans, all revving like buggery?

Bill

On Wed, 18 Mar 2015 13:31:35 -0000, Bill Wright wrote:

Tough Guy no. 1265 wrote:

I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...lz?utm_source=

newsletter&utm_medium=email&utm_term=15P13_W4_D3&u tm_content=Product-1&utm_campaign=15P13-20


"Ideal for powering devices such as laptops". **** me, that's overkill
isn't it?

What if it's got twin GPUs? Anyway, no harm in having extra power in case you need it. You never know what things you might want to plug in.

--
Give a person a fish and you feed them for a day. Teach a person to use the Internet and they won't bother you for weeks, months, maybe years.

Not if it's the front lawn and the car is on the road.

On Wed, 18 Mar 2015 08:00:27 -0000, Brian Gaff wrote:

But those tyre marks on the other end of the lawn are a bit awkward...
Brian



--
A conclusion is simply the place where someone got tired of thinking.

In message , at 13:33:00 on Wed, 18 Mar
2015, Bill Wright remarked:

I think he had 4 gel batteries of about 800Ah each.

That's a bit big. A narrowboat would typically have four 110Ah batteries
for the 'hotel power' and a fifth one to start the engine in the
morning.

Must have been a bloody big boat! I wouldn't fancy that sort of weight
except in the bilge!

That's where you put the batteries, plus even more ballast usually. I've
seen scrap iron, paving slabs, all sorts of things.
--
Roland Perry

In article , Bill Wright
wrote:
Syd Rumpo wrote:
On 17/03/2015 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...5000w-12v-powe

-inverter-a59lz?utm_source=newsletter&utm_medium=email&utm_t erm=15P13_W4_D3&utm_content=Product-1&utm_campaign=15P13-20




What possible use is it? How many people have got 12v batteries
capable of delivering 500 amps for more than a few minutes (more
likely a few *seconds"!)?

An outdoor concert, run from a van with its engine running, fairly
quickly?

You don't get anything like 500A out of a van alternator. A row of ten
vans, all revving like buggery?

our survey vehicles got 2 x 250VA out of a Range Rover alternator - and
that was 40+ years ago.

--
From KT24 in Surrey

Using a RISC OS computer running v5.18

On 18/03/15 13:34, Bill Wright wrote:
Syd Rumpo wrote:
On 17/03/2015 20:52, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...5000w-12v-powe

-inverter-a59lz?utm_source=newsletter&utm_medium=email&utm_t erm=15P13_W4_D3&utm_content=Product-1&utm_campaign=15P13-20




What possible use is it? How many people have got 12v batteries capable
of delivering 500 amps for more than a few minutes (more likely a few
*seconds"!)?

An outdoor concert, run from a van with its engine running, fairly
quickly?

You don't get anything like 500A out of a van alternator. A row of ten
vans, all revving like buggery?

Bill

500A for several minutes from a typical car battery

More from a few in parallel



--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

On Tuesday, March 17, 2015 at 8:52:20 PM UTC, Roger Mills wrote:
I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...paign=15P13-20

What possible use is it?

Someone who lives on a boat who wants to run an electric cooker off a marine alternator?

Robert

On 18/03/2015 13:33, Bill Wright wrote:
whisky-dave wrote:



I think he had 4 gel batteries of about 800Ah each.


Must have been a bloody big boat! I wouldn't fancy that sort of weight
except in the bilge!

Bill

Its a canal boat, they were used to carry 100 tons of stuff about, a few
small batteries doesn't matter unless you put them on the roof where
someone will knick 'em..

In message , at 15:25:35 on
Wed, 18 Mar 2015, charles remarked:

our survey vehicles got 2 x 250VA out of a Range Rover alternator - and
that was 40+ years ago.

I used to have a Land Rover with twin 24v alternators[1] and 24
batteries. That was to power the army field radio station that it
originally had installed in the back. (keyword: FFR)

[1] 2.4kW each, according to a quick Google, so that's 200amps total.
--
Roland Perry

On 18/03/2015 08:42, HarpingOn wrote:
On 18/03/2015 07:58, Brian Gaff wrote:
Sounds a bit expensive as well even with the discount.
You would need some serious sized battery leads and about five heavy duty
lorry batteries to stand any chance of being able to use it near its
limit
and of course what about charging them up?
Brian


Run a battery charger off the inverter output.

Trouble is that the Maplin advert will appeal to the sort of person who
would think that that was a good idea!
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 18/03/2015 13:31, Bill Wright wrote:
Tough Guy no. 1265 wrote:

I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...lz?utm_source=


newsletter&utm_medium=email&utm_term=15P13_W4_D3&u tm_content=Product-1&utm_campaign=15P13-20


"Ideal for powering devices such as laptops". **** me, that's overkill
isn't it?

Bill

It does say laptops - in the plural. It would probably power about 100
at a time!
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 18/03/2015 15:25, charles wrote:
In , Bill
wrote:


You don't get anything like 500A out of a van alternator. A row of ten
vans, all revving like buggery?

our survey vehicles got 2 x 250VA out of a Range Rover alternator - and
that was 40+ years ago.


So that's just over 40 amps then - nothing like 500!
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Wed, 18 Mar 2015 16:53:17 -0000, Roger Mills wrote:

On 18/03/2015 13:31, Bill Wright wrote:
Tough Guy no. 1265 wrote:

I see that Maplin have a 5000watt mains inverter on offer for £350
instead of £600

http://www.maplin.co.uk/p/maplin-dc-...lz?utm_source=


newsletter&utm_medium=email&utm_term=15P13_W4_D3&u tm_content=Product-1&utm_campaign=15P13-20


"Ideal for powering devices such as laptops". **** me, that's overkill
isn't it?

Bill

It does say laptops - in the plural. It would probably power about 100
at a time!

The description is probably copied form the smaller models.

--
Seen in a lift:
"Please do not allow excessive obnoxious gaseous substances to be released from your anal orifice as the ventilation system is limited".

"Syd Rumpo" wrote in message
...
On 18/03/2015 09:56, john james wrote:

snipped


"Andrew Gabriel" wrote in message
...
In article ,
"john james" writes:
"Roger Mills" wrote in message
...

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever
that is.

It's a set of steps that are close to a sinewave than a square wave is.

It's often a square wave with the addition of an elongated zero section
at each zero crossing.

That's not modified sine wave.


'Tis, Google it. Rectangular pulses +ve and -ve with gaps between. I
designed one - filthy noisy thing.

I meant that that is a modified square wave, not a modified sine wave.

On 18/03/2015 18:51, john james wrote:


"Syd Rumpo" wrote in message
...
On 18/03/2015 09:56, john james wrote:

snipped


"Andrew Gabriel" wrote in message
...
In article ,
"john james" writes:
"Roger Mills" wrote in message
...

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever
that is.

It's a set of steps that are close to a sinewave than a square wave
is.

It's often a square wave with the addition of an elongated zero section
at each zero crossing.

That's not modified sine wave.


'Tis, Google it. Rectangular pulses +ve and -ve with gaps between. I
designed one - filthy noisy thing.

I meant that that is a modified square wave, not a modified sine wave.

It may well be a modified square wave, in literature and specifications
it is generally described as a "modified sine wave".

"Andrew Gabriel" wrote in message
...
In article ,
"john james" writes:
"Roger Mills" wrote in message
...

It would also depend on how sensitive your electrical equipment is to
waveform. It claims to produce a "modified" sine wave - whatever that
is.

It's a set of steps that are close to a sinewave than a square wave is.

It's often a square wave with the addition of an elongated zero section
at each zero crossing. Sometimes, there's the addition of one extra
voltage step between zero and the peak.

Fine for resistive loads.

Works with many inductive loads, but may run at reduced power, and
cause extra eddy current heating in laminated cores (with audiable
noise).

Not so good with capacitive loads and capacitor dropper supplies,
where the impedance of the capacitor is reduced by the high frequency
components, causing higher current than appliance designed for, and
usually extra power dissipation somewhere.

If you need them, pure sine wave inverters have come down very
significantly in price over last couple of years. They are basically
a sine wave generator coupled to a power amplifier with a 230V RMS
output. The amplifier is class D, i.e. high frequency switching, so
the efficiency is almost as high as the "modified" sine wave
inverters (or it can even match, as they're generally better designed,
and the efficiency of the appliance can also be higher in some cases).


My Dad has a pure sine wave invertor. Just to power up the CH, the TV and a
couple of lamps and a small travel kettle if needed.

https://www.tlc-direct.co.uk/Products/SK652105.html

Several people said it would not work with his CH but it did:-)

--
Adam

In message , at 19:44:43 on Wed, 18 Mar
2015, ARW remarked:
If you need them, pure sine wave inverters have come down very
significantly in price over last couple of years. They are basically
a sine wave generator coupled to a power amplifier with a 230V RMS
output. The amplifier is class D, i.e. high frequency switching, so
the efficiency is almost as high as the "modified" sine wave
inverters (or it can even match, as they're generally better designed,
and the efficiency of the appliance can also be higher in some cases).

My Dad has a pure sine wave invertor. Just to power up the CH, the TV
and a couple of lamps and a small travel kettle if needed.

I've got a 3KVA UPS which I hope produces something close to a
sine-wave. It's got about 30Kg of metal inside (as transformer cores)
and originally cost someone about $2000. I've never found anything that
objected to the output.
--
Roland Perry